Z-Wave is a wireless communications protocol with interoperability that is developed by Zensys which is a Danish company and Z-Wave Alliance, is designed for an apparatus requiring low power and low bandwidth such as home automation device, a sensor network, or the like, and uses a bandwidth with a transmission speed of 9,600 bit/s or 40 Kbit/s and a Gaussian frequency-shift keying (GFSK) modulation scheme.
Further, since it is possible to perform communication outdoors up to about 100 feet, and configure maximum 232 units and networks, a frequency bandwidth of 900 MHz on average is allocated and used globally, and in Korea, it is provided that frequency bandwidths of 919.6 MHz, 921.6 MHz, and 923.1 MHz are used to control a home automation device.
Such a Z-Wave is an RF technology that is most widely used to control the home automation (HA) device currently, and low power consumption, 2-way RF, mesh networking technology, and battery-to-battery support are suitable for controlling sensors and devices. In particular, unlike Zigbee, Z-Wave is interoperated with products of different vendors at an application level, and is cheaper. Due to the advantages described above, currently, 100 or more products of different vendors that may be directly purchased by a consumer have been released in the market.
According to the related art, in most apparatuses, in order to control the home automation device by a portable terminal and the Internet, a network system is configured by a wired/wireless LAN communication scheme. In particular, the wireless LAN does not have a routing function, and has low obstacle transmittance, thus it is difficult to wirelessly control the device in a house with a large area and many obstacles, a lot of information is required to be input at the time of connection, and a connection procedure is complicated, such that it is difficult for an ordinary person to use the device.
Zigbee using 2.4 Ghz frequency band has a similar function to that of Z-Wave. However, since protocol schemes for controlling a smart device of manufacturers are different from each other, it may be difficult to implement interworking, and since most wireless communication frequencies using the wireless LAN use 2.4 GHz frequency band, data loss caused by frequency collision may not be avoided.
Meanwhile, Z-Wave uses a protocol based on IEEE 802.15.4 which is one of standard technologies for low rate wireless personal area networks (LR-WPANs) to facilitate interworking between home automation devices, and has a routing function to configure a network while bypassing an obstacle, thereby securing a longer transmission distance as compared to a transmission distance of a single network.
Accordingly, there is a need to construct a system capable of controlling a home automation device in a more stable and wider-range communication environment by a portable terminal from the outside by embedding a Z-Wave communication protocol in a set-top box connecting between the home automation device and the portable terminal, and the home automation device.